nuttx/arch/arm/src/samv7/sam_oneshot.h
Petro Karashchenko 1fd51ccbe2 arch/arm/samv7: rework SAMv7 timer counter implementation
There are two issues that are addressed with this change:
 - According to SAM E70/S70/V70/V71 Family datasheet the
   timer counter channels are 16-bit so timer counter
   value should be changed from uint32_t to uint16_t
 - The interrupt handling for timer counter channels can
   be simplified

Signed-off-by: Petro Karashchenko <petro.karashchenko@gmail.com>
2022-01-09 17:43:31 +08:00

209 lines
8.0 KiB
C

/****************************************************************************
* arch/arm/src/samv7/sam_oneshot.h
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
****************************************************************************/
#ifndef __ARCH_ARM_SRC_SAMV7_SAM_ONESHOT_H
#define __ARCH_ARM_SRC_SAMV7_SAM_ONESHOT_H
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <stdint.h>
#include <time.h>
#include "sam_tc.h"
#ifdef CONFIG_SAMV7_ONESHOT
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
#define ONESHOT_INITIALIZED(s) (((s)->tch) != NULL)
/****************************************************************************
* Public Types
****************************************************************************/
/* This describes the callback function that will be invoked when the oneshot
* timer expires. The oneshot fires, the client will receive:
*
* arg - The opaque argument provided when the interrupt was registered
*/
typedef void (*oneshot_handler_t)(void *arg);
/* The oneshot client must allocate an instance of this structure and called
* sam_oneshot_initialize() before using the oneshot facilities. The client
* should not access the contents of this structure directly since the
* contents are subject to change.
*/
struct sam_oneshot_s
{
uint8_t chan; /* The timer/counter in use */
volatile bool running; /* True: the timer is running */
TC_HANDLE tch; /* Handle returned by
* sam_tc_initialize() */
volatile oneshot_handler_t handler; /* Oneshot expiration callback */
volatile void *arg; /* The argument that will accompany
* the callback */
#ifdef CONFIG_SAMV7_FREERUN
volatile uint16_t start_count; /* Stores the value of the freerun counter,
* at each start of the oneshot timer. Is necessary
* to find out if the oneshot counter was updated
* correctly at the time of the call to
* sam_oneshot_cancel or not. */
#endif
};
/****************************************************************************
* Public Data
****************************************************************************/
#undef EXTERN
#if defined(__cplusplus)
#define EXTERN extern "C"
extern "C"
{
#else
#define EXTERN extern
#endif
/****************************************************************************
* Public Function Prototypes
****************************************************************************/
/****************************************************************************
* Name: sam_oneshot_initialize
*
* Description:
* Initialize the oneshot timer wrapper
*
* Input Parameters:
* oneshot Caller allocated instance of the oneshot state structure
* chan Timer counter channel to be used. See the TC_CHAN*
* definitions in arch/arm/src/samv7/sam_tc.h.
* resolution The required resolution of the timer in units of
* microseconds. NOTE that the range is restricted to the
* range of uint16_t (excluding zero).
*
* Returned Value:
* Zero (OK) is returned on success; a negated errno value is returned
* on failure.
*
****************************************************************************/
int sam_oneshot_initialize(struct sam_oneshot_s *oneshot, int chan,
uint16_t resolution);
/****************************************************************************
* Name: sam_oneshot_max_delay
*
* Description:
* Return the maximum delay supported by the one shot timer (in
* microseconds).
*
* Input Parameters:
* oneshot Caller allocated instance of the oneshot state structure. This
* structure must have been previously initialized via a call to
* sam_oneshot_initialize();
* usec The location in which to return the maximum delay.
*
* Returned Value:
* Zero (OK) is returned on success; a negated errno value is returned
* on failure.
*
****************************************************************************/
int sam_oneshot_max_delay(struct sam_oneshot_s *oneshot, uint64_t *usec);
/****************************************************************************
* Name: sam_oneshot_start
*
* Description:
* Start the oneshot timer
*
* Input Parameters:
* oneshot Caller allocated instance of the oneshot state structure. This
* structure must have been previously initialized via a call to
* sam_oneshot_initialize();
* freerun Caller allocated instance of the freerun state structure. This
* structure must have been previously initialized via a call to
* sam_freerun_initialize(). May be NULL if there is no matching
* free-running timer.
* handler The function to call when when the oneshot timer expires.
* arg An opaque argument that will accompany the callback.
* ts Provides the duration of the one shot timer.
*
* Returned Value:
* Zero (OK) is returned on success; a negated errno value is returned
* on failure.
*
****************************************************************************/
struct sam_freerun_s;
int sam_oneshot_start(struct sam_oneshot_s *oneshot,
struct sam_freerun_s *freerun,
oneshot_handler_t handler, void *arg,
const struct timespec *ts);
/****************************************************************************
* Name: sam_oneshot_cancel
*
* Description:
* Cancel the oneshot timer and return the time remaining on the timer.
*
* NOTE: This function may execute at a high rate with no timer running (as
* when pre-emption is enabled and disabled).
*
* Input Parameters:
* oneshot Caller allocated instance of the oneshot state structure. This
* structure must have been previously initialized via a call to
* sam_oneshot_initialize();
* freerun Caller allocated instance of the freerun state structure. This
* structure must have been previously initialized via a call to
* sam_freerun_initialize(). May be NULL if there is no matching
* free-running timer.
* ts The location in which to return the time remaining on the
* oneshot timer. A time of zero is returned if the timer is
* not running.
*
* Returned Value:
* Zero (OK) is returned on success. A call to up_timer_cancel() when
* the timer is not active should also return success; a negated errno
* value is returned on any failure.
*
****************************************************************************/
struct sam_freerun_s;
int sam_oneshot_cancel(struct sam_oneshot_s *oneshot,
struct sam_freerun_s *freerun, struct timespec *ts);
#undef EXTERN
#ifdef __cplusplus
}
#endif
#endif /* CONFIG_SAMV7_ONESHOT */
#endif /* __ARCH_ARM_SRC_SAMV7_SAM_ONESHOT_H */